...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Environmental Science & Technology >Mechanisms of Physically Irreversible Fouling during Surface Water Microfiltration and Mitigation by Aluminum Electroflotation Pretreatment
【24h】

Mechanisms of Physically Irreversible Fouling during Surface Water Microfiltration and Mitigation by Aluminum Electroflotation Pretreatment

机译：铝电浮选预处理在表面水微滤和减缓过程中物理不可逆结垢的机理

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A modified poly(vinylidene fluoride) membrane was used to directly microfilter untreated Lake Houston water, which was then regenerated by surface washing and hydraulic backwashing, a process that was cycled five times. The source water was also electrochemically precoagulated using aluminum and microfiltered, and the membrane was physically regenerated for five cycles. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) were used to characterize foulants on membrane surfaces and rigorously deduce their contributions to physically irreversible fouling after cycles 1 and 5. Hydrophobic molecules primarily appeared to initiate fouling during microfiltration of untreated raw water because O-H/N-H bands were attenuated while C-H bands remained relatively unchanged in FTIR-spectra of membrane surfaces after only one cycle. However, O-H/N-H and symmetric and asymmetric C(=O)O~- stretching bands significantly intensified with continued filtration/ regeneration of untreated water, showing the importance of hydrophilic molecules and the role of complexation, respectively, to longer term irreversible fouling. Distinct C-H bands were detected in floated flocs after electrolysis, suggesting the sorption and subsequent removal of a substantial portion of the hydrophobic moieties present in Lake Houston water during pretreatment. Consequently, hydrophilic compounds appeared to contribute more to irreversible fouling in pretreated waters throughout the course of filtration as evidenced by significantly more intense O-H bands (compared with C-H bands) on the membrane surface after cycles 1 and 5. Therefore, electroflotation pretreatment reduced accumulation of hydrophobic foulants but simultaneously increased complexation of hydrophilic foulant molecules along with any carried-over aluminum hydroxide precipitates evidenced by increasing Al and O concentrations via XPS and intense C(=O)O~- stretching bands in IR spectra.
机译：改性聚偏二氟乙烯膜用于直接微过滤未经处理的休斯敦湖水，然后通过表面清洗和水力反冲洗将其再生，该过程循环了五次。还使用铝对源水进行了电化学预凝结并进行了微过滤，并对膜进行了5次循环物理再生。衰减全反射-傅立叶变换红外光谱（ATR-FTIR）和X射线光电子能谱（XPS）用于表征膜表面上的污垢，并严格推断出它们在循环1和5后对物理不可逆结垢的贡献。在未经处理的原水微滤过程中会引发结垢，因为仅一个循环后，OH / NH谱带衰减，而膜表面的FTIR光谱中CH谱带保持相对不变。然而，随着未处理水的持续过滤/再生，O-H / N-H以及对称和不对称的C（= O）O〜-拉伸带显着增强，分别显示了亲水性分子的重要性和络合作用对长期不可逆结垢的作用。电解后在漂浮的絮状物中检测到明显的C-H条带，表明在预处理过程中存在于休斯敦湖水中的大部分疏水部分被吸附并随后被去除。因此，在循环的整个过程中，亲水性化合物似乎对预处理水中不可逆结垢的贡献更大，如循环1和循环5后膜表面上明显更强烈的OH谱带（与CH谱带相比）所证明的。因此，电浮选预处理可减少水的积累。疏水性污垢，但同时增加了亲水性污垢分子与任何残留的氢氧化铝沉淀物的络合，这通过XPS和IR光谱中强烈的C（= O）O〜-拉伸带增加了Al和O的浓度来证明。

著录项

  • 来源
    《Environmental Science & Technology》 |2014年第2期|1148-1157|共10页
  • 作者

    Neranga P. Gamage; Shankararaman Chellam;

  • 作者单位

    Department of Civil and Environmental Engineering, University of Houston, Texas 77204-4003, United States;

    Department of Civil and Environmental Engineering, University of Houston, Texas 77204-4003, United States,Department of Chemical and Biomolecular Engineering, University of Houston, Texas 77204-4004, United States;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号